Friction type dipper trip



June 13, 1933. G. ca. MORIN FRICTION TYPE DIPPER TRIP 2 Sheets-Sheet 1Original Filed May 1'7, 1930 MM MM M N \w QM Q\ \N I I A QM m-\\\w\\\\\\\ N\ k K 7% M Q m N Q Q 3 5 Q w o Q Q o Y O o O O o f 0 O 0\KQW 2W June 13, 1933 G; G MORIN FRICTION TYPE DIPPER TRIP OriginalFiled May 1'7, 1950 2 Sheets-Sheet 2 A TTORNEYS.

Patented June 13 1933 UNITED STATES PATENT OFFICE GEORGE G. MORIN, orHOLYOKE, MASSACHUSETTS FRICTION TYPE DIPPE-R 'IRIP Application filed May17, 1930, Serial No. 453,272. Renewed November 4,1932.

This invention relates to power mechanism for tripping the bottom of thedipper on an excavating machine and has specific reference to that formof power dipper tripping device which is operated by means of friction.It is the general object of the inventlon to improve prior devices ofthis character by simplifying their construction and, therefore,providing a dipper trip having a minimum number of parts. A furtherobject is toprovide a friction type dipper trip in which the pull of thetripping cable is always derived from a single source, whether the cableis tensioned only to the point of taking up its slack or tensioned.further until the latch mechanism of the dipper bottom is actuated.

.The invention will now be described with reference to the accompanyingdrawings, in which Fig. 1 is a side elevation, partly in section, of anexcavating machine having myimproved dipper trip attached thereto;

Fig. 2 is a perspective detailof a spring member;

mechanism shown in Fig. 5; 1

Fig. 4 is a sectional detail of the mechanism for supplying tension tothe tripping cable; and 1 V Fig. 5 is a detail similar to Fig. 4 butshowing the parts in different positions.

An excavating machine hasbeen shown conventionally in Fig. 1. Itpossesses the usual cab 10 containing the power units and serving as asupport for the excavatingparts.

A boom 11 is pivoted at 12 to the cab and carries a dipper handle 13hearing at its end the dipper 14. These parts may be actuated by any ofthe usual types of mechanism. The

bottom 15 of the dipper is hinged at 16 to the dipper body, and latchmechanism indicated generically at 17 is provided to release the dipperbottom when deslred. This mecha nism also may be of any desired type,one

form being illustrated in my prior'applica- Fig. 3 is a fragmentary topplan view of tion Serial No. 413,890, filed December 13, 1929. Extendingfrom the latch mechanism is the usual tripping cable 18 passing overguides 19 and being wound upon a drum 20.

The drum 20 is mounted upon a sleeve 21 freely rotatable upon aturned-down end 22 of a constantly rotating shaft 23 which mayconveniently be the shaft supplying power for the actuation of thevarious movements of the excavating machine. A disk 24 bear- 5 ing afriction facing 25 is pinned at 26 tothe shaft. At the opposite side ofthe drum 20 from the disk 24 the shaft is provided with a slot 27 intowhich fits a spring 28 and a key 29. The spring 28 shown in detail inFig. 2 is provided with a pin 30 adapted to extend into a hole 31 formedin the shaft 23 adjacent the slot. The spring is also formed withturned-down ends 32 which assist in keeping it in position The key 29 issecured to a pin (.5 33 slidable in a hole in the shaft 23 which isaligned with the hole 31 previously mentioned. By this means the key mayslide from the position of Fig. 4 in which the spring is compressed tothe position of Fig. 5 in which '6; most of the compressive action onthe spring has been removed. I

In the case chosen for illustration, the portion of the shaft to whichthe tripping mechanism is applied overhangs the hearing; and as it isnecessary to prevent rotation of certain parts of the trip operatingmechanism, a member 34 is loosely mounted upon the end of the shaft 23and is securedby a pin 35 to a bracket 36 fixed upon the cab relative tothe shaft. While the shaft turns freely within the member, relativeaxial movement is prevented by a nut 37 hearing against the memberthrough intervention of a washer 38. Secured to the member 34 is a.housing 39 internally threaded-to receive a screw 40. This screw isprovided with a conically recessed end 41, between which and the end ofthe pin 33 ispositioned a ball 42. At the end of the screw a pulley 43is secured by a pin 44. A cord 45 is secured in a groove in the pulleyand extends to a spring 46 which is strained between it and a stationarypart of the machine. A second cord 47 is secured in another groove ofthe pulley and extends over a guide roll 48 to the end of a handle 49pivoted to one of the machine control levers 50.

The operation of the device will now be considered. The normal positionof the mechanism is that shown in Fig. 5. The shaft 23 and the disk 24are constantly rotating and the drum 20 is pressed against the frictionsurface 25 by the slight tension of spring 28. This pressure issufficient to cause rotation of the drum but is not enough to exert anysubstantial tension upon the cable 18 above that which is required forthe removal of any slack which may form in the cable due to the movementof the dipper from one position to another. As the dipper is moved aboutthe cable will be constantly kept taut by the tendency of the drum toturn whenever permitted by the pressure of slack in the cable.

vVhen it is desired to trip the dipper, the handle 49 is depressed. Thisrotates the screw 40 by means of the cord 47 and pushes the pin 33 tothe position of Fig. 4. It will be noted that in this figure the spring28 has been completely compressed so that direct pressure is appliedtothe end of the sleeve 21, this pressure being directly regulated bythe pull on the handle 49 and not by the force of the spring 28. Underthese condi tions the pressure between the drum 20 and the friction face25 is increased to a point where the tension on the cable 18 issufficient to trip the latch mechanism 17. It will be observed that asingle friction contact is maintained and that the change in tension onthe cable is secured by varying the pressure with which the frictionalelements bear against each other.

The device has been described in its preferred embodiment as a dippertrip.- The same device can, however, be used as a tag line winder forpreventing a clam shell bucket or hook block from twisting; or as aslack take-up on a clam shell bucket holding line. In such cases thespring may be changed to provide the constant pressure necessary, andthe extra pull resulting from the shifting of key 29 utilized to givetemporary tugs on the line, as for opening the clam shell bucket or forresisting a sudden tendency of the bucket or block to twist.

What I claim is:

1. A cable tensioning device capable of use as a dipper trip or tag linewinder comprising a constantly rotating shaft, a cable-recelving drumrotatably and slidably mounted upon said shaft, a disk fixed upon theshaft and having a friction facing in contact with one end of the drum,a key slidably mounted in a slot in the shaft at the other end of thedrum, a fiat bow spring in the slot and interposed between the key andthe drum, a stationary abutment, a screw threaded into the abutment,connections between the screw and the key, and means under the controlof the operator for rotating the screw to shift the key in the slot froma position where the only axial pressure on the drum is due to thespring to a position where the key exerts positive pressure upon thedrum.

2. A cable tensioning device capable of use as a dipper trip or tag linewinder, comprising a constantly rotating shaft, a cable-receiving drumrotatably and slidably mounted upon said shaft, a disk fixed upon theshaft and having a friction facing in contact with one end of thedrum, akey slidably mounted in a slot in the shaft at the other end of thedrum, a flat bow spring located in the slot and interposed between thekey and the drum, and means operable during rotation of the shaft forshifting the key in the slot from a position where the only axialpressure on the drum is due to the spring to a position where the keyexerts positive pressure upon the drum.

3. A cable tensioning device capable of use as a dipper trip or tag linewinder comprising a constantly rotating shaft, a cable receiving drumrotatably and slidably mounted on the shaft, a member fixed upon theshaft and having frictional engagement with the drum, meansnon-rotatable with the shaft and operable during the rotation thereoffor forcing the drum against the member with a pressure sufficient togive to the drum a turning force sufiicient to produce relatively heavytension in the cable, and yieldable means forcing the drum against themember with a lesser pressure when the first means is released, saidlesser pressure being sufiicient to take up any slack in the cable.

4. A cable tensioning device capable of use as a dipper trip or tag linewinder'comprising a constantly rotating shaft, a cablereceiving drumrotatably and slidably mounted upon the said shaft, a disk fixed uponthe shaft and having a friction facing in contact with one end of thedrum, a key slidably mounted in a slot in the shaft at the other end ofthe drum, a spring interposed between the key and the drum, and meansnon-rotatable with the shaft and operable during the rotation thereoffor shifting the key in the slot from a position where the only axialpressure on the drum is due to the spring to a position where the keyexerts positive pressure on the drum.

5. A cable tensioning device capable of use drum, means non-rotatablewith the shaft and operable during-the rotation thereof for forcing thedrum against the member with a pressure sufficient 'to producerelatively heavy tension in the cable, and a replaceable spring actingupon the drum when said means is in inoperative position to hold thedrum against the member with a lesser pressure, said spring beingrendered inactive and the pressure of the drum against the member madepositive instead of yielding by the action of said means.

6. A cable tensioning device capable of 7 use as a dipper trip or tagline winder comprising a constantly rotating shaft, a cable receivingdrum rotatably and slidably mounted on the shaft, a member fixed upon,

the shaft and having frictional engagement with the drum, an abutmentrelatively stationary with respect to the drum, a spring interposedbetween the abutment and the drum, and means for pushing the drumpositively away from the abutment and against the member, the springcausing a normal yielding pressure between the drum and the member andhaving its effective yielding action superseded by the positive pressureof said means when said means is actuated.

7 A cable tensioning device capable ofv use as a dipper trip or tag lineWinder comprising a constantly rotating shaft, a cable receiving drumrotatably and slidably mounted upon the said shaft, a disk fixed uponthe shaft and having a friction face in contact with one end of thedrum, a member slidable relative to the shaft, means nonrotatable withrespect to the shaft and movable axially with respect thereto to causesaid member to push the drum positively against the disk, and a springacting upon the drum when said means is not actuated to cause the drumto be pressed yieldingly against the disk, the spring being sopositioned that its yielding pressure on the drum is superseded by thepositive pressure of said means when the latter is actuated.

In testimony whereof I have aflixed my signature.

GEORGE G. MORIN.

